MakeHuman Inverse Kinematics
It looks like you have too many IK constraints on your legs and arms. You should have just on per leg or arm (on the shin or forearm bones) and then set the targets to the foot or hand, and the chain length to the number of bones in the leg arm. To avoid bending on the twist bones at the top of each arm/leg, you will need to adjust the settings to lock particular axes on the bone ik panel in pose mode.

See https://www.blender.org/manual/rigging/armatures/posing/bone_constraints/inverse_kinematics/introduction.html